By the age of 29, Blake Mycoskie had already started and run four companies. But on a trip to Argentina in 2006, he found the inspiration to start the company he says he'll work at the rest of his life.

Mycoskie is the 31-year-old founder of Toms Shoes, a company that donates one pair of shoes to someone in need for each pair it sells.

While in Argentina, Mycoskie met a group of children in a village he visited. Struck by their lack of shoes and the consequences they faced because of it (ranging from foot injuries and diseases to being ostracized), he decided he would provide footwear for these children and others like them around the world. While figuring out how to do it, Mycoskie decided he didn't want to create a charity. "I wanted it to be sustainable, and I didn't want the burden of fundraising year after year, so I created a business," he says.

Mycoskie modeled his first designs off the alpargata--a traditional Argentine shoe--but used higher-end materials to ensure comfort and durability. At a price point of $40, he's built in a big enough margin to pay for the extra pairs of shoes that will be donated. Within six months of opening for business in 2006, Toms Shoes had given away 10,000 pairs of shoes, far exceeding Mycoskie's projection of 250 pairs.

The growth of the company has relied primarily on word-of-mouth. Mycoskie says that he hasn't had to spend money on advertising because his customers are walking billboards. "When someone asks customers about [the shoes], they'll tell the whole story of the company. They feel good that a child somewhere is wearing shoes because they bought some," he explains.

Toms Shoes now sells in 200 boutiques across the country, as well as in Bloomingdale's, Nordstrom and online at tomsshoes.com. So far, the company has given away more than 63,000 pairs of shoes in both Argentina and South Africa. Mycoskie concedes that he'll never have the profit margins of other successful shoe companies, but nobody is more pleased about the business than he is. "I had no desire to get into shoes. It started as a philanthropic thing. But I have really fallen in love with the shoe and fashion business."

JJ Ramberg is the host of MSNBC's small-business program Your Business and co-founder of GoodSearch.com.